Water-Based Cleaning

Abstract

A method of cleaning a surface, comprising applying de-gassed water (containing no more than 1 ppm gas) to the surface to disperse or dissolve dirt on the surface in the water. The method may also comprise dissolving hydrophobic dirt on the surface using a non-aqueous solvent, and dispersing the non-aqueous solvent and dissolved hydrophobic dirt in the de-gassed water. The non-aqueous solvent may itself contain low levels of dissolved gas, for example no more than 10 ppm. Apparatus for cleaning a surface is also disclosed.

1 . A method of cleaning a surface, comprising applying water containing no more than 1 ppm gas to the surface to disperse or dissolve dirt on the surface in the water. 
   
   
       2 . A method according to  claim 1 , wherein the water contains no more than about 0.9 ppm gas. 
   
   
       3 . A method according to  claim 1 , wherein the water contains no more than about 0.3 ppm gas. 
   
   
       4 . A method according to  claim 1 , wherein the water contains no more than about 3 ppb gas. 
   
   
       5 . A method according to  claim 1 , wherein the water contains no more than about 0.3 ppb gas. 
   
   
       6 . A method according to  claim 1 , wherein the surface is on an article and wherein the method comprises cleaning the article in the water in a container. 
   
   
       7 . A method according to  claim 6 , wherein one or both of the article and water are agitated. 
   
   
       8 . A method according to  claim 1 , wherein the water is applied to the surface by spraying. 
   
   
       9 . A method according to  claim 8 , wherein the water is sprayed on to the surface by means of an airless spray system. 
   
   
       10 . A method according to  claim 1 , which comprises applying multiple streams of the water to the surface to agitate dirt on the surface. 
   
   
       11 . A method according to  claim 1 , wherein the water contains hydrophilic stabilising material to alleviate redeposition of the dirt on the surface. 
   
   
       12 . A method according to  claim 1 , which comprises using a stored source of the water containing no more than 1 ppm gas. 
   
   
       13 . A method according to  claim 1 , which includes de-gassing a source of water to a level of no more than 1 ppm gas. 
   
   
       14 . A method according to  claim 1 , which comprises dissolving hydrophobic dirt on the surface using a non-aqueous solvent, and dispersing the non-aqueous solvent and dissolved hydrophobic dirt in the water. 
   
   
       15 . A method according to  claim 14 , wherein the non-aqueous solvent is applied to the surface prior to applying the water to the surface. 
   
   
       16 . A method according to  claim 15 , wherein the surface is relatively separated from a liquid body of the non-aqueous solvent prior to applying the water to the surface. 
   
   
       17 . A method according to  claim 14  wherein the non-aqueous solvent applied to the surface contains no more than about 10 ppm gas. 
   
   
       18 . A method according to  claim 17 , wherein the non-aqueous solvent applied to the surface contains no more than about 1 ppm gas. 
   
   
       19 . A method according to  claim 17 , wherein the non-aqueous solvent applied to the surface contains no more than about 0.3 ppm gas. 
   
   
       20 . A method according to  claim 17 , wherein the non-aqueous solvent applied to the surface contains no more than about 3 ppb gas, 
   
   
       21 . A method according to  claim 17 , wherein the non-aqueous solvent applied to the surface contains no more than about 0.3 ppb gas. 
   
   
       22 . A method according to  claim 17 , which comprises using a stored source of the non-aqueous solvent containing no more than 10 ppm gas. 
   
   
       23 . A method according to  claim 17 , which includes de-gassing the non-aqueous solvent to a level of no more than 10 ppm gas. 
   
   
       24 . A method according to  claim 14 , wherein the non-aqueous solvent is hydrophobic. 
   
   
       25 . A method according to  claim 14 , wherein the non-aqueous solvent is selected from hydrocarbons, fluorocarbons, chloro-hydrocarbons, silicone liquids and mixtures of one or more of same. 
   
   
       26 . A method according to  claim 25 , wherein the non-aqueous solvent is selected from dodecane, squalene, hexamethyldisiloxane, perfluorohexane, hexane and mixtures of one or more of same. 
   
   
       27 . Apparatus for cleaning a surface, comprising a source of water containing no more than 1 ppm gas and a dispenser for applying the water to the surface. 
   
   
       28 . Apparatus according to  claim 27 , wherein the surface is on an article and the apparatus includes a container for receiving the article. 
   
   
       29 . Apparatus according to  claim 28 , which includes an agitator for one or both of the article and water. 
   
   
       30 . Apparatus according to  claim 27 , wherein the dispenser comprises a sprayer. 
   
   
       31 . Apparatus according to  claim 30 , wherein the sprayer is part of an airless spray system. 
   
   
       32 . Apparatus according to  claim 27 , wherein the dispenser applies multiple streams of the water to the surface to agitate dirt on the surface. 
   
   
       33 . Apparatus according to  claim 27 , wherein the source of water comprises a store of the water containing no more than 1 ppm gas. 
   
   
       34 . Apparatus according to  claim 27 , wherein the source of water comprises equipment for de-gassing water to a level of no more than 1 ppm gas. 
   
   
       35 . Apparatus according to  claim 27 , which includes a source of non-aqueous solvent and a dispenser for applying the non-aqueous solvent to the surface. 
   
   
       36 . Apparatus according to  claim 35 , wherein one dispenser is used for applying the water and the non-aqueous solvent. 
   
   
       37 . Apparatus according to  claim 35 , wherein the source of the non-aqueous solvent comprises a store of the non-aqueous solvent. 
   
   
       38 . Apparatus according to  claim 35 , wherein the source of nonaqueous solvent comprises equipment for de-gassing non-aqueous solvent to a level of no more than 10 ppm gas.